Gene therapy is a promising approach for improving and restoring vision. Particularly, delivery of genes, such as photosensitive proteins, to diseased or damaged retinas in mice have been recently shown to improve and restore photosensitivity and visual signals. However, challenges still remain for the efficient targeting and expression of such genes in specific inner retinal neurons for ocular gene therapy. Accordingly, there is a pressing need for improved regulatory elements and expression vectors for the delivery and expressing of transgenes for ocular gene therapy.